Arven was a male squirrel of Redwall Abbey. As a Dibbun, he was a very good friend of Tansy and had a special nickname for her, "Tansy Pansy". When out searching for herbs with Tansy, he accidentally fell into a hole containing the skeleton of the weasel Graylunk, which spurred the search for the Tears of all Oceans.

He was the ringleader of a Dibbun group including Diggum and Gurrbowl, two moles. He often led them into mischief and could always be found making trouble somewhere; one time he ventured out into Mossflower Woods believing that when he was found he would be praised. Despite this, he contributed to the search for the pearls on several occasions.